This invention relates generally to internal combustion engines and more specifically devices for enhancing the combustion of fuel in an internal combustion engine.
Internal combustion engines use a mixture of air and liquid fuel which is ignited by means of a spark in a combustion chamber. The most efficient combustion occurs when the liquid fuel is volatilized into a vapor prior to entry into the combustion chamber. However, present carburation techniques for liquid fuel still result in fuel reaching the combustion chamber primarily in liquid form. The presence of fuel almost completely in liquid form in the combustion chamber produces an inefficient and incomplete combustion having products which reduce the life of the engine and are also harmful to the environment. The contamination to the engine caused by reaction products such as unburned hydrocarbons, increases the maintenance requirements of the engine (e.g., oil changes and tune ups). Moreover, the combustion of liquid gasoline and air requires more energy than is required for the combustion of a mixture of liquid fuel, fuel vapor and air. This inefficiency results in an increase in fuel consumption.
It is known to increase the presence of fuel in vapor form by heating liquid fuel to produce vapor which is mixed with the air flow to the combustion chambers of the engine (e.g., U.S. Pat. No. 4,398,523). However the production of vapor solely by heating is not sensitive to changes in the demand for fuel by the engine, and does not employ other forms of energy available in the engine to promote vaporization of the fuel. Moreover, the equipment required to vaporize fuel solely by heating is typically large and not easily incorporated into existing internal combustion engine systems.